Re: Small tip proposal for headless systems boot resiliency

[M <mathieu%lubrano.at@localhost>]

> Le 31 déc. 2013 à 17:27, Hubert Feyrer <hubert%feyrer.de@localhost> a écrit :
> 
>> On Tue, 31 Dec 2013, Robert Elz wrote:
>> My basic strategy would be to enhance fstab in some yet to be determined way
>> to indicate which filesystems were optional, them simply ignore (without
>> mounting obviously) any optional filesystem that has a problem (or whose
>> parent filesystem could not be mounted) and only abort the boot if a
>> non-optional filesystem failed to check & mount.   Since in my case my
>> non-optional filesystems are (in practice) all remarkably stable (as in
>> nothing much important normally changes on them - the only significant
>> changes are the newsyslog updates, and for me, they don't often do anything,
>> so they are unlikely to have fsck problems) this would allow the system to
>> get up and running in situations where now it stops and waits for
>> attention.
> 
> from /etc/defaults/rc.conf:
> 
>    # Filesystems to mount early in boot-up.
>    # Note that `/var' is needed in $critical_filesystems_local (or
>    # implied as part of `/') as certain services that need /var (such as
>    # dhclient) may be needed to get the network operational enough to mount
>    # the $critical_filesystems_remote.  Prepending "OPTIONAL:"  means it
>    # will not be an error if that file system is not present in fstab(5).
>    #
>    critical_filesystems_local="OPTIONAL:/var"
>    critical_filesystems_remote="OPTIONAL:/usr"
> 
> Maybe that can serve as starting point...
> 
> 
> - Hubert
> 

Regarding filesystem issues, it seems fair to use rc.conf settings and some 
scripting rather than modifying fstab (it may be read and parsed by others). 
And it may help recovering for most common boot issues.

On the stop_boot side, still I don't like the idea of rc scripts possibly 
halting the whole boot sequence just for their own concern.
Depending on the use case it's à good or bad thing, yet to me it should be a 
rc.conf and sysadmin decision.

Bye,
Mathieu Lubrano.